ONOS-542 Defining application subsystem interfaces & public constructs.

Change-Id: Iba0d2cb69dace5beee8a68def9918059ce755b5c
diff --git a/core/api/src/main/java/org/onosproject/app/ApplicationDescription.java b/core/api/src/main/java/org/onosproject/app/ApplicationDescription.java
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+++ b/core/api/src/main/java/org/onosproject/app/ApplicationDescription.java
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+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.app;
+
+import org.onosproject.core.Permission;
+import org.onosproject.core.Version;
+
+import java.net.URI;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * Description of a network control/management application.
+ */
+public interface ApplicationDescription {
+
+    /**
+     * Returns the application name id.
+     *
+     * @return application identifier
+     */
+    String name();
+
+    /**
+     * Returns the application version.
+     *
+     * @return application version
+     */
+    Version version();
+
+    /**
+     * Returns description of the application.
+     *
+     * @return application description text
+     */
+    String description();
+
+    /**
+     * Returns the name of the application origin, group or company.
+     *
+     * @return application origin
+     */
+    String origin();
+
+    /**
+     * Returns the permissions requested by the application.
+     *
+     * @return requested permissions
+     */
+    Set<Permission> permissions();
+
+    /**
+     * Returns the feature repository URI. Null value signifies that the
+     * application did not provide its own features repository.
+     *
+     * @return optional feature repo URL
+     */
+    Optional<URI> featuresRepo();
+
+    /**
+     * Returns the set of features comprising the application. At least one
+     * feature must be given.
+     *
+     * @return application features
+     */
+    Set<String> features();
+}